Method and apparatus for making a decision on a card

ABSTRACT

Method and devices for making access decisions in a secure access network are provided. The access decisions are made by a portable credential using data and algorithms stored on the credential. Since access decisions are made by the portable credential non-networked hosts or local hosts can be employed that do not necessarily need to be connected to a central access controller or database thereby reducing the cost of building and maintaining the secure access network.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 14/017,065, filed Sep. 3, 2013, which is a continuation of U.S.patent application Ser. No. 13/274,863, filed Oct. 17, 2011, now U.S.Pat. No. 8,578,472, which is a continuation of U.S. patent applicationSer. No. 11/778,145, filed Jul. 16, 2007, now U.S. Pat. No. 8,074,271,which claims the benefit of U.S. Provisional Application No. 60/821,897,filed Aug. 9, 2006, the entire disclosures of which are herebyincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to access control systems,devices, and methods. More specifically, the present invention providesan access control system in which authentication decisions are made on acredential.

BACKGROUND

In prior art access control systems, for example as shown in FIG. 1,typically credentials 120 (or other equivalent tokens) are used toauthenticate a user to a system. These systems often employcryptographic protocols, such as ISO 9798-2, to effect mutualauthentication between the system and the card. Access is granted whenthe system recognizes the user, finds the privileges for the user in adatabase, and makes the decision based on the user's privileges outlinedin the database. In all these prior art systems the credential 120 isprimarily an information carrier; little use is made of processing powerinherent in the credential 120.

In many prior art systems, the database is centralized. FIG. 1 depicts acentralized access control system 100 with a centralized database 104.The benefit of a centralized database in access control is the ease ofdata management, speed, and consistency with which data updates areshared in the access control system 100. However, such prior art systemssuffer from high installation costs. If the access control decision ismade centrally, then the locks and/or access points 108 are networked(either wired or wirelessly) to a central server or control panel 112.This is expensive. In the case of wired networks, there are costsassociated with materials and labor because the wiring must bephysically installed between all system components. In the case ofwireless networks, there are increased costs associated with ensuringreliable and secure communication between all network nodes.

Another drawback of these prior art systems is their reliance on aphysically or wirelessly connected network 116. Such reliance can causeservice interruptions when the network is not available. Prior artsystems typically do not store policy information (i.e., informationused to grant or deny access to a credential 120) at access points suchas a door. Instead the system operates in reduced-mode whencommunication is lost. Storing policy information at the door ispossible in prior art systems, but at a higher cost due to bothequipment and maintenance.

Other prior art systems, such as those found in WO04025545 and U.S. Pat.No. 6,719,200 make authentication checks based on biometric informationusing a networked connection and a credential 120 or other processordevice. In these types of prior art systems, a biometric template isstored on the credential 120 and a second biometric template is createdfrom a biometric scan taken in response to an access request. The secondbiometric template is stored in a database 104 on the network 116 andsent to the credential 120 upon presentation of the credential 120 to anaccess reader. These systems use biometrics for authentication that canlater lead to a control decision after user rights are checked, but thecredential's processor does not make the access control decision.Rather, the credential's processor verifies that the biometric datareceived from the network database matches biometric data stored on thecredential 120 before any further communications are initiated by thecredential with a reader for purposes of gaining access. In thesesystems the reader still makes the ultimate access control decision.

In other prior art systems, policy information from the database 104 isdistributed among non-networked locks. In these prior-art systems, themanagement of the policy information is problematic. Updating thedatabases may be accomplished by special reprogramming visits bysecurity personnel, but this is expensive in time, especially in a largesystem having numerous non-networked locks. Alternatively, the lockdatabase is updated via a pseudo-network created on the user cards, suchas the one discussed in WO05024549A2. In these systems, datagramnetworking techniques pass database records from central system tonon-networked locks by additional messaging between user card and lock,see for example U.S. Pat. No. 6,766,450. Typically, systems based onthis model involve passing a large amount of data between the user cardand the lock, which slows the access control process and makes theexperience unpleasant for the user, and consumes energy. This can be aserious detriment in the case of battery-powered locks where powerconsumption is at a premium.

In yet other prior art systems, such as those described in U.S. Pat. No.6,374,356, the database of policy information for each user is carriedon the card itself. For example, if a user is privileged to open acertain subset of doors in the system, then the card holds informationto that effect. In these prior art systems, the lock reads the databaserecord from the card, then the lock determines if the user privilegesinclude opening the lock. In large systems, the access control databaserecord may contain a relatively large amount of data that must be passedto the lock. This transfer of data again slows the access controlprocess and consumes energy.

Database management and transmitted policy information described in theprior art are both processes that can consume significant amounts oftime and energy. Energy use is an important consideration forapplications where the local door device is battery operated.

SUMMARY

In one embodiment, the problem associated with updating disconnectedreaders is addressed by obviating the need for policy information to betransferred from the credential to the reader. In accordance with atleast one embodiment of this invention, the credential holds policyinformation and the local host transfers information needed to make anaccess decision to the credential. The credential uses its processor tomake the enforcement decision and transfers the decision or results ofthat decision to the local host.

While embodiments of the invention do not preclude the capability oftransmitting identity information from the credential to the reader,some embodiments may provide the additional capability of securelyenforcing control policy without disclosing the credential identity.Moreover, embodiments of the present invention can be used with anetworked control system or in a distributed control system.Additionally, certain embodiments of the invention offer a cost savingmeans by making it possible to create an access control system that isexpandable with non-networked readers.

It is one objective of the present invention to provide a secure accesscontrol system capable of working with non-networked hosts (localhosts), in which a reader of the local host contains no database, and inwhich a minimal amount of communication is required between the localhost and the credential.

Aspects of the invention address technical problems inherent in priorart systems by having the policy information or user privilege data onthe credential and the access control decision made using thecredential's microprocessor and communicated to an access control deviceassociated with the local host.

In one embodiment, a local host need only authenticate with thecredential using an appropriate protocol, which are well known in theprior art, and transmit to the credential an ID and/or functionalidentification. After mutual authentication, time and date informationare passed from the local host to the credential. This represents arelatively small amount of data and is virtually independent of systemsize. It should be noted that scalability of the system may depend onadditional required messaging, such as a Certificate Revocation List(CRL). As can be appreciated by one of skill in the art, CRLs presentjust one way to invalidate a user. A CRL can be used if the credentialinformation is digitally signed. More generally, however, a list ofrevoked credentials may be employed.

According to one embodiment of the present invention, each credentialcarries unique privilege information for the credential user, which mayinclude a list of local host or door ID numbers, timestamps, accessschedule information, security class information, and additional rulesor controls relevant to the user's access authorizations. Thisinformation might be coded as a list of door ID numbers, or as a set ofrules, or in other ways which are well known to those skilled in theart.

In one embodiment, the processor on the credential runs an algorithm,contained on the credential, to determine if the credential holderprivileges allow the credential user to open the door or access theasset protected by the local host. If the decision is made that thecredential user is granted access, then a secure message is sent to thedoor or local host requesting the access control device (e.g., a lock)to open.

If the processor on the credential determines that the credential useris not allowed access to the asset, then no further action is required.Alternatively, if a no-access decision by the credential is made, thecredential may send a code to the reader, which allows both the readerand credential to record an unauthorized attempt to gain access. Therecord may be stored at the reader, the credential, or both. This typeof information related to an unauthorized access attempt might be usefulfor later investigation or security analysis.

It is assumed that privileges and algorithms residing on the credentialcan be periodically and securely maintained by appropriate means, suchas connection to or communication with a central database by acredential reader/writer. The reader/writer may be associated with a PC,workstation, or at a networked access-control point. This is preferableof prior art schemes where a database is updated periodically on thereader, because the reader is typically stationary and may be remote,whereas the credential is mobile and typically carried by the userwherever he might require to use it. The credential can therefore bebrought to the reader/writer rather than bringing the reader/writer toall local hosts.

Expiration of the privileges on the credential (e.g., to preventunauthorized use of a lost or misplaced credential) may be enforced bytime-stamping the privileges on the credential, or by other knownmechanisms. In any case, the processor on the credential may still makethe access control decision by running an algorithm.

In one embodiment, the access control system comprises one or morenon-networked door locks otherwise known as local hosts, one or morecredentials, one or more credential reader/writers, and a central accesscontrol system including a master database and system administratorinterface.

The local host, in one embodiment, comprises an access control deviceand a controller. The controller preferably utilizes a microprocessor, arandom number generator or alternatively a secure seed and apseudo-random number generator, a cryptographic coprocessor, and controlcircuitry to operate the blocking mechanism (e.g., a lock, passwordprotection program, or the like). The local host may further include apower source such as a battery or a solar cell, volatile and nonvolatilememory, a real-time clock, and a Radio Frequency Identification (RFID)reader or other communication mechanism.

The credential, in one embodiment, comprises a communication mechanism,for example, either an RFID antenna or electrical contacts typical to acontact credential 216, and a smartcard controller. The credential 216controller generally comprises a microprocessor, RFID or othercommunications circuitry, a random number generator, a cryptographiccoprocessor, and volatile and non-volatile memory. Preferably the memoryand circuitry of the credential and the local host are designedutilizing security features to prevent unauthorized access to the memorycontents, side channel analysis, and the like.

In a transaction, the reader of the local host supplies its ID andcurrent date and time information to the credential. The credentialcontains access privilege data, normally specific to the credentialholder. Based on the ID and time, coupled with the privileges data, thecredential decides if the credential holder may access the assetprotected by the local host.

In one embodiment, if access is granted, then the credential issues asecure “unlock request” to the local host. If access is not granted,then no action need be performed. As can be appreciated, a system basedon embodiments of this invention can be made secure against playback andother simple attacks by employing suitable cryptographic techniques inauthentication and messaging.

The Summary is neither intended or should it be construed as beingrepresentative of the full extent and scope of the present invention.The present invention is set forth in various levels of detail and theSummary as well as in the attached drawings and in the detaileddescription of the invention and no limitation as to the scope of thepresent invention is intended by either the inclusion or non inclusionof elements, components, etc. in the Summary. Additional aspects of thepresent invention will become more readily apparent from the detaileddescription, particularly when taken together with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a centralized access control system in accordance withembodiments of the prior art;

FIG. 2 depicts an access control system in accordance with embodimentsof the present invention;

FIG. 3 depicts components of a local host in accordance with embodimentsof the present invention;

FIG. 4 depicts components of a credential in accordance with embodimentsof the present invention;

FIG. 5 depicts logical data components of the access control system inaccordance with embodiments of the present invention;

FIG. 6 depicts a method of initializing a credential with access data inaccordance with embodiments of the present invention;

FIG. 7 depicts a method of refreshing access information on a credentialin accordance with embodiments of the present invention;

FIG. 8 depicts a method of operating a local host in accordance withembodiments of the present invention; and

FIG. 9 depicts a method of authenticating a credential with local hostin accordance with embodiments of the present invention.

DETAILED DESCRIPTION

Embodiments of the present invention are directed toward devices andmethods of using such devices in a secure access system. Although wellsuited for use in systems and methods employing RF communicationprotocols, embodiments of the present invention may be suitable for usein systems employing other communication protocols including, but notlimited to, optical communication protocols, magnetic communicationprotocols, and the like.

FIG. 2 depicts a secure access system 200 in accordance with at leastsome embodiments of the present invention. The secure access system 200generally includes a privilege server 204 and a validation server 208that communicate with one or more credentials 216 through areader/writer 212. The privilege server 204 and validation server 208are dedicated servers that provide certain services to credentials 216in the system 200. Although depicted separately, a single server orsimilar device may execute the functionality of both the privilegeserver 204 and the validation server 208. The privilege server 204and/or validation server 208 are capable of communicating with thereader/writer 212 via any known communication protocol such as InternetProtocol (IP) standard or the like.

The privilege server 204 initializes, modifies, and changes applicationsand application data stored on a credential 216 by using the writingfeature of the reader/writer 212. The privilege server 204 can increaseor decrease the scope of the privileges associated with the credential.The privilege server 204 has access to a user database that identifieswhat access permissions various users in the system 200 have. When acredential 216 is presented to the reader/writer 212, the privilegeserver 204 accesses data on the credential 216 using a symmetric key,Kp, that is shared between the privilege server 204 and the credential216. Of course, the key, Kp, may also be an asymmetric key or other typeof secret. Then the privilege server 204 can identify who the holder ofthe credential 216 is or is supposed to be. Once the privilege server204 knows the identity of the holder it can generate the appropriateaccess permissions and write those permissions to the credential 216 inthe form of application data. Additionally, the privilege server 204 canwrite an application to the credential 216 that is used by thecredential 216 to make access decisions based, in part, on theapplication data. The privilege server 204 stores application data thatincludes, but is not limited to, schedule data (i.e., access permissionsdata by time), local host data (i.e., access permissions by local host),timestamp data, and authentication keys for each credential 216 in thepopulation of credentials 216 in the access control system 200. Theapplication data for each credential 216 may be stored in a portion ofmemory in the privilege server 204 or in a separate database. Theprivilege server 204 also has access to the current time either by anInternet connection, an internal clock, or by some other mechanism.

The validation server 208 is provided to refresh the application on acredential 216 with a privilege expiration, typically in the form of atimestamp. The validation server 208 does not increase the scope of theprivileges associated with a credential, other than by extending thetime existing credentials are valid. The validation server 208 hasaccess to the current time. The validation server 208 also has access tothe current validation status of all access control privileges for everycredential holder. Validation status information may be stored either inmemory of the validation server 208 or in an external database. When acredential 216 is presented to the reader/writer 212, the validationserver 208 determines if the credential's status is still active andalso determines if the schedule data on the credential 216 is current.If both are true, then the validation server 208 sets a new expirationfor the application data on the credential 216. Of course, thevalidation server 208 does not have to set a new expiration if currentdata is not expired. Otherwise, the application data is left alone suchthat it either remains expired or will expire after a predeterminedexpiration period, or may renew it, even if expired if such instructionsare in the system.

The reader/writer 212 acts as a communication conduit between thecredential 216, privilege server 204, and validation server 208. As canbe appreciated, a separate and dedicated reader/writer 212 may beprovided for both the privilege server 204 and the validation server208. Additionally, the reader/writer 212 may also be a networkedreader/writer 212 associated with an access point in the access controlsystem 200. A networked reader/writer 212 may read and performauthentication with the credential 216 and then act as a communicationconduit between the credential 216 and the validation server 208. Thesystem may also be a single server with both the privilege andvalidation functionality working through a single reader/writer. Theremay also be multiple reader/writers connected in a network at differentlocations to permit credentials to be updated or validated at physicallydifferent locations but under the control of a single administrativesystem.

The credential 216 may be any suitable type of access control device. Inone embodiment, the credential 216 is capable of making real-time ornear real-time access decisions. In other words, the credential 216 iscapable of determining whether it is granted or denied access to variousassets in the secure access system 200. The credential 216 storesapplication data that includes access permissions and algorithms formaking access decisions. The credential 216 may be provided with aunique ID that distinguishes it over other credentials 216 in thepopulation of credentials 216. In one embodiment, the credential ID,application data, and other data stored on the credential 216 isprotected using various symmetric keys. The credential 216 generallyincludes an RF transponder that enables the credential 216 tocommunicate using contactless communication protocols. Examples of asuitable credential 216 include, but are not limited to, a contactlesssmartcard, a passport, a key fob, a cellular phone, a PDA, portablecomputer, or any other device having appropriate functionality.Alternatively, the credential 216 may be in some other machine-readableform. For example, the credential 216 may employ magnetic, optical, orcontact communication methods.

Using any type of communication protocol, the credential 216 is capableof communicating with a local host 220 a-N. A local host 220 is any typeof non-networked access point. The local host 220 controls access to oneor more assets such as a building, room, computer, database, file, andso on. The local host 220 is typically assigned a unique ID thatidentifies the host or the asset protected by the host. In oneembodiment, the host ID is passed to the credential 216 in order for thecredential 216 to have enough information to make an access decision. Ina preferred embodiment, the local host 220 only needs to supply its hostID and the current time to the credential 216.

Referring now to FIG. 3, an exemplary reader/writer 212 or local host220 will be described in accordance with at least some embodiments ofthe present invention. The reader/writer 212 or local host 220 generallycomprises a reader 304 capable of automatically reading data from acredential 216. The reader 304 may also be capable of writing data backto the credential 216. The reader 304, in one embodiment, comprises anRF antenna used to communicate back and forth with the credential 216.

Connected to the reader 304 is a controller 308. In one embodiment, thecontroller 308 includes a microprocessor, a random number generator, anda cryptographic coprocessor. The controller 308 is capable of properlymodulating/demodulating data sent to and received from external devicessuch as the credential 216. The controller 308 controls and determineshow the reader/writer 212 or local host 220 behaves when a credential216 is presented to it. The controller 308 may include anygeneral-purpose programmable processor, digital signal processor (DSP)or controller for executing application programming. Alternatively, thecontroller 308 may comprise a specially configured application specificintegrated circuit (ASIC).

The controller 308 may also be provided with control circuitry capableof manipulating an access control device 312. The access control device312 is designed to secure the asset being protected by the reader/writer212 or local host 220. Examples of a typical access control device 312include, without limitation, an electronic lock, a magnetic lock, or anelectric strike for a door, a lock for a computer system, a lock for adatabase, a lock on a financial account, or a lock on a computerapplication. In one embodiment, the controller 308 actuates the accesscontrol device 312 based on results of an access decision provided tothe controller 308 from the credential 216. The access control device312 may be integral to the reader/writer 212 or local host 220 in oneembodiment. In an alternative embodiment, access control device 312 isexternal to the reader/writer 212 or local host 220.

In addition to an access control device 312, the reader/writer 212 orlocal host 220 may further comprise a memory 316. The memory 316 may beused to store application data, the host unique ID, and any otherfunctions that can be executed by the controller 308. The memory 316 maycomprise volatile and/or non-volatile memory. Examples of non-volatilememory include Read Only Memory (ROM), Erasable Programmable ROM(EPROM), Electronically Erasable PROM (EEPROM), Flash memory, and thelike. Examples of volatile memory include Random Access Memory (RAM),Dynamic RAM (DRAM), Static RAM (SRAM), or buffer memory. In oneembodiment, the memory 316 and the controller 308 is designed to utilizeknown security features to prevent unauthorized access to the contentsof the memory 316 such as side channel analysis and the like.

The reader/writer 212 or local host 220 may further comprise a clock320. The clock 320 is depicted as internal to the reader/writer 212 orlocal host 220, but the clock may also be external to the reader/writer212 or local host 220. The clock 320 tracks the current time. Thecontroller 308 can read the time from the clock 320 and provide thattime to a credential 216. The credential 216 uses the time from theclock 320 to determine if the holder of the credential 216 is currentlyallowed access to an asset protected by the access control device 312.

A power source 324 may also be included in the reader/writer 212 orlocal host 220 to provide power to the various devices contained withinthe reader/writer 212 or local host 220. The power source 324 maycomprise internal batteries and/or an AC-DC converter such as a switchmode power supply or voltage regulator connected to an external AC powersource.

Although not depicted, a reader/writer 212 may further include acommunication interface that provides communication capabilities betweenthe reader/writer 212 and external servers or other network nodes. Sucha communication interface may include a USB port, a modem, a networkadapter such as an Ethernet card, or any other communication adapterknown in the art.

Referring now to FIG. 4, an exemplary credential 216 will be describedin accordance with at least some embodiments of the present invention.The credential 216 may include a communication interface 404 that allowsthe credential 216 to communicate with external devices such as thereader/writer 212 or local host 220. The communication interface 404 maycomprise an RF antenna that allows the credential 216 to receive andtransmit data without contact. In other embodiments a magnetic, optical,or electrical contact communication interface 404 may be utilized.

A controller 408 may be connected to the communication interface 404.The controller 404, in one embodiment, includes a microprocessor, arandom number generator, and a cryptographic coprocessor. The controller408 may include any general-purpose programmable processor, digitalsignal processor (DSP) or controller for executing applicationprogramming. Alternatively, the controller 408 may comprise a speciallyconfigured application specific integrated circuit (ASIC). Similar tothe controller 308 on the reader/writer 212 or local host 220, thecontroller 408 includes known security features that substantiallyprevent unauthorized access to the contents of memory 412.

The memory 412 typically comprises non-volatile memory, such as flashmemory. Non-volatile memory is generally used because the credential 216is preferably a passive credential meaning that it does not have aninternal source of power. Rather, the credential 216 uses energy from anRF field created by the reader/writer 212 or local host 220 to power itscomponents. Contents of the memory 412 may include an access decisionapplication 416. As noted above, the privilege server 204 may write theaccess decision application 416 along with application data to thecredential 216. In a preferred embodiment, the access decisionapplication 416 and application data are written to the credential 216in a secure environment. The access decision application 416 contains analgorithm or algorithms that can be used to make an access decision. Thecontroller 408 can access the access decision application 416 andapplication data to make an access decision with respect to a particularreader/writer 212 or local host 220.

In an alternative embodiment the credential 216 may be provided with anonboard power supply. Such credentials 216 are known as activecredentials 216. An active credential 216 can keep its own trusted timethat can be synchronized with the network devices during interactionswith the privilege server 204 and/or validation server 208. FIG. 5depicts logical components of each device in the secure access system200 in accordance with at least some embodiments of the presentinvention. The memory 412 of the credential 216 generally containsapplication data and an access decision application 416. The memory 412may also include credential specific data such as a credential ID 504and a privilege key Kp 508. The memory 412 may also include an operatingsystem 512 that defines the normal functionality of the credential 216.

The access decision application 416 is a second program or algorithmthat may be stored on the memory 412. The access decision application416 may be given a unique application ID 516 that distinguishes thisapplication from other applications, such as the operating system 512,that are stored in memory 412. A symmetric application key Ka 520 isalso stored in memory 412. The application key Ka protects access to theapplication data. The application key Ka may be shared uponinitialization of the system or creation of the application with thevalidation server 208. The application key Ka 520 is typically differentfrom the privilege key Kp used by the privilege server 204 to access andrewrite the entire access decision application 416. The application keyKa 520 is required to update or modify the expiration of the accessdecision application 416. Also stored in the memory 412 in associationwith the access decision application is a user ID 524. The user ID 524identifies the intended user of the credential 216. The user ID 524 maybe an arbitrary identifier such as a randomly assigned number or may bethe user's social security number, employee number, or the like. Theuser of the credential 216 is assigned the user ID 524 for use with theaccess decision application 416. The user ID 524 is employed by theprivilege server 204 to assign user access permissions and by thevalidation server 208 to update access permissions. The user ID 524 isgenerally not needed for use with a local host 220.

As previously noted, application data may be stored as a part of theaccess decision application 416. A set of application data issubstantially unique to a particular application and therefore issubstantially unique to certain local hosts 220. For example, a firstset of application data may be used to make access decisions for roomsin a building. A second set of application data may be used to makeaccess decisions for a garage door or the like whereas a third set ofapplication data may be used to make access decisions related toelectronic files or programs.

In one embodiment, a first set of application data includes a controlkey KD1 528, a control or access schedule 532, and an expiration time536. The control key KD1 528 is shared with the local host(s) 220 thatwill be used in association with the first application. The control keyKD1 528 is used by the local host 220 and credential 216 to authenticatewith one another. The control schedule 532 is a logical combination ofthe credential's 216 access permissions by time as well as thecredential's 216 access permission by local host 220. The accessdecision application 416 uses the control schedule 532 to determine ifaccess should be granted or denied for the holder of the credential 216with respect to a particular reader/writer 212 or local host 220. Theexpiration 536 controls the useful life of the application data and isgenerally only updated by the validation server 208. If the expiration536 has lapsed or expired then the control schedule 532 is renderedinvalid until it is presented to a validation server 208 and theexpiration 536 is updated again. The credential 216 will be incapable ofmaking an access decision for any local host in the first application ifthe expiration 536 for that application has caused the control schedule532 to be rendered invalid.

More than one set of application data may be stored in the accessdecision application 416. A second set of application data may include acontrol key KD2 540, a control schedule 544, and an expiration 548. Thesecond set of application data is substantially unique to the secondapplication and thus preferably runs the second application independentof the first application. For example, the lapse of the first expiration536 does not necessarily mean that the second expiration 548 has lapsed.

Although two application data blocks are depicted in FIG. 5, one skilledin the art will appreciate that a lesser or greater number ofapplication data blocks may reside on the credential 216. In oneembodiment, there may be a different application data block for eachlocal host 220 in the secure access system 200.

In addition to application data, the access decision application 416 mayalso store access history in a log file 552. The log file 552 containsdata related to access decisions made by the credential 216. Both accessgranted decisions and access denial decisions along with thecorresponding time of decision and reader/writer 212 or local host 220are stored in the log file 552. The log file 552 can be accessed todetermine the whereabouts and actions of the holder of the credential216.

A timestamp 556 may also be stored as a part of the access decisionapplication 416. The timestamp 556 represents the most recent time thatthe credential 216 was accessed by a reader/writer 212 or local host220. Comparison of the timestamp 556 and expiration 536, 548 maydetermine whether a particular application should be rendered invalid bydeactivating the control schedule 532, 544.

The privilege server 204 generally stores data for managing theprivileges of the population of credentials 216. The type of dataavailable to the privilege server 204 for each credential 216 in thepopulation of credentials 216 may include a privilege key Kp 572, anapplication key Ka 576, a credential ID list with access permissionsdata 580, and the current time 584. The data for all credentials 216 maybe stored in a separate database that can be accessed by the privilegeserver 204. The privilege server 204 identifies a particular credential216 and pulls relevant data for that credential 216 into the fieldsdescribed above using the privilege key Kp 572. The privilege server 204employs the application key Ka 576 to authenticate with the credential216. Once the privilege server 204 is authenticated using theapplication key Ka 576, the privilege server 204 can modify the accessdecision application 416 and any application data associated therewith.

The use of the keys Kp 572 and Ka 576 may involve the transmission of anencrypted random or pseudorandom message. The privilege server 204typically has a random number generator and in the event that thecredential 216 does not have a random number generator, the privilegeserver 204 can provide the random message for the credential 216 to usein authentication.

As noted above, once the privilege server 204 has identified thecredential 216 and has pulled the relevant access permissions data 580,the privilege server 204 can write or modify the access decisionapplication 416 along with the current time 584. The current time 584may be stored by the credential 216 as the timestamp 556.

The validation server 208 generally stores data for managing theexpiration of application data on credentials 216. The type of dataavailable to the validation server 208 for each credential 216 in thepopulation of credentials 216 may include an application key Ka 560, acredential status 564, and the current time 568. The validation server208 employs the credential status 564 data to determine if thecredential's 216 expirations 536, 548 should be updated or removed. Thecurrent time from the validation server 208 may also be written to thetimestamp 556 data field in the access decision application 416.

Each local host 220 a-N may store unique data to the host or theapplication employed by the host in their respective memories 316 a-N.The type of data stored in a local host 220 may include a local host ID586, a control key KD1 590, and the current time 594. The control keyKD1 590 is used to authenticate with a credential 216 and morespecifically to authenticate with a particular set of application datastored in the application decision application 416. Once authenticated,the local host ID 586 and current time 594 are provided to thecredential 216 such that an access decision can be made by thecredential 216.

Referring now to FIG. 6, a method of initializing a credential 216 willbe described in accordance with at least some embodiments of the presentinvention. Initially, the method begins with the privilege server 204authenticating with the credential 216 (step 604). The privilege server204 uses its privilege key Kp 572 and the credential 216 uses itsprivilege key Kp 508 to authenticate with one another. As noted above,the authentication step may involve the transmission of an encryptedrandom message between the credential 216 and privilege server 204.

Once the privilege server 204 and credential 216 are properlyauthenticated, the privilege server 204 acquires the credential ID 504from the credential 216 (step 608). The privilege server 204 referencesa credential database with the credential ID 504 to eventually pull theaccess permissions for the particular credential 216 (or holder of thecredential 216) presented to the privilege server 204. The privilegeserver 204 then creates the access decision application 416 (step 612).The access decision application 416 includes at least one set ofapplication data. More sets of application data may be included in theaccess decision application 416 if more than one application is to berun by the same credential 216.

After the access decision application 416 has been created, theprivilege server 204 assigns a unique user ID 524 to the application(step 616). Other devices in the network 200 will ultimately use theunique user ID 524 to determine if the application 416 is still valid.The privilege server 204 then retrieves the associated user accesspermissions data 580 from the network using the credential ID 504 (step620). The user access permissions data 580 define what reader/writers212 or local hosts 220 the user is allowed to access and the times theuser is allowed to access them. This user access permissions data 580along with the user ID 524 is written to the credential 216 as a part ofthe access decision application 416 (step 624).

Upon writing the application to the card, or soon thereafter, theprivilege server 204 also writes expirations 536, 548 for each set ofapplication data included in the access decision application (step 628).The expirations 536, 548 can be a timing based instruction to eitherdelete a particular set of application data or render the correspondingcontrol schedule 532 invalid and thus unusable. After a set ofapplication data has expired, the credential 216 will need to bepresented to a reader/writer 212 such that either a privilege server 204or validation server 208 can update the expirations 536, 548.Alternatively, the expirations 536, 548 may be valid and can remainunchanged. It should be noted that separate access decision applicationsfor separate application data may be sequentially or simultaneouslycreated.

Referring now to FIG. 7, a method of refreshing an access decisionapplication 416 will be described in accordance with at least someembodiments of the present invention. Initially, a credential 216 ispresented to the validation server 208 (step 704). The presentation ofthe credential 216 to the validation server 208 may be through acommunication conduit provided by a reader/writer 212. Upon presentationof the credential 216 to the validation server 208, authenticationbetween the credential 216 and the validation server 208 occurs (step708). The credential 216 uses application key Ka 520 to authenticatewith the validation server 208 and the validation server 208 usesapplication key Ka 560 to authenticate with the credential 216. Theapplication keys Ka 520, 560 are shared symmetric keys unique to theaccess decision application 416. The authentication step helps ensurethat both devices know they are communicating with a valid device.

After mutual authentication, the validation server 208 acquires the userID 524 from the credential 216 (step 712). Using the user ID 524, thevalidation server 208 acquires the application data for the presentedcredential 216 or holder of the credential 216 (step 716). Theapplication data for the presented credential 216 can be obtained fromperiodic updates of the user's application data from the privilegeserver 204 or by accessing the privilege server 204 in real-time. Thevalidation server 208 then analyzes the application data for thepresented credential 216 to determine if the access permissions for thatcredential 216 are still valid (step 720). In the event that the accesspermissions are no longer valid, then the validation server 208invalidates the control schedule(s) 532, 544 that were identified asinactive (step 724). Access permissions may become invalid for a numberof reasons. For example, the holder of the credential 216 may have beenterminated or had his/her permissions changed and therefore theapplication data stored on the credential 216 is out no longer valid.Alternatively, the access permissions may require updating and theapplication data has not been updated within the predetermined time.

The control schedule 532, 544 can be invalidated by executing theexpiration function 536, 548 corresponding to the inactive controlschedule 532, 544. Alternatively, access to the control schedule 532,544 can be restricted thus inhibiting the credential 216 from making anaccess decision. In one embodiment, a control schedule 532, 544 ismarked invalid by setting the timestamp to all zeros. In anotherembodiment control schedules 532, 544 are marked invalid by setting theexpiration to a time in the past or to a different prescribed invalidcode.

In the event that the access permissions are still valid, the methodcontinues and the validation server 208 updates the schedule expiration536, 548 if appropriate or necessary (step 728). The expiration 536, 548may be updated both in the network as well as the credential 216. Thereader/writer 212 may be used to write the updated expiration 536, 548to the credential 216. Updating the expiration 536, 548 may includeadding additional time to the expiration counter or changing theexpiration date.

Once the expiration 536, 548 has been updated, the validation server 208sends an approval signal back to the reader/writer 212 (step 732). Thereader/writer 212 may then grant the holder of the credential 216 accessto the asset protected by the reader/writer 212. Alternatively, a lightor similar type of indicator may be activated showing the credential 216holder that the expiration 536, 548 has been successfully updated.

With reference now to FIG. 8, a method of operating a local host 220will be described in accordance with at least some embodiments of thepresent invention. Initially, when a credential 216 is presented to alocal host 220, the local host 220 transmits its local host ID 586 tothe credential 216 (step 804). The local host ID 586 uniquely identifiesthe local host 220 or the application employed by the local host 220 tothe credential 216. Upon receipt of the local host ID 586, thecredential 216 locates the local host ID 586 in its application data 416(step 808). More specifically, the credential 216 identifies that thelocal host ID 586 is being used in connection with the access decisionapplication 416 and the control schedules 532, 544 of each set ofapplication data is searched for a matching local host ID 586. When thelocal host ID 586 is found, the control key KD 528, 540 is pulled fromthe corresponding set of application data. The chosen control key KD528, 540 is used by the credential 216 to authenticate with the localhost 220 (step 812).

After the credential 216 and local host 220 have mutually authenticatedwith one another, the local host 220 reads the timestamp data 556 fromthe credential 216 (step 816). The local host 220 uses the timestamp 556to determine if its own current time 594 is way off from the actual time(assuming the timestamp 556 accurately reflects actual time). The localhost 220 can use the timestamp 556 to perform an option step where thelocal host 220 checks to see if the timestamp 556 is greater than thecurrent time 594 (step 820). The optional step 820 is provided as acheck to ensure that the local host 220 clock is not running too slow.In the event that the timestamp 556 is greater than the current time594, then the local host 220 updates its current time 594. Theassumption behind the local host 220 updating its time to match the timefrom the timestamp 556 is because the credential 216 is able tocommunicate with networked devices such as a reader/writer 212 thatreceive their current time from a live and presumably more accuratesource such as the Internet. Therefore, the credential 216 timestamp 556can be updated whenever it is presented to a networked device.

Once the current time 594 is updated or determined to be accurate, thelocal host 220 transmits the current time 594 to the credential 216(step 828). The credential 216 then uses the access decision application416 to compare the received current time against the control schedule532, 544 for the appropriate application (step 832). After running theaccess decision application 416 the credential 216 determines whether itis allowed to access the asset protected by the local host 220. In otherwords, the access decision application 416 determines whether thecurrent time 594 is within the control schedule 532, 544 for the assetassociated with the local host (step 836). In other words, the accessdecision application 416 may determine if access is granted to the localhost 220 as well as specify that access is currently allowed for thelocal host 220 to which the credential 216 is presented. If the currenttime is not within the control schedule 532, 544 (i.e., the credential216 is not allowed access to the asset), then no action is performed orthe credential 216 sends a denied access message to the local host 220(step 840). On the other hand, if the credential 216 determines that itshould be allowed access to the asset based on the analysis of thecontrol schedule 532, 544, then the credential 216 sends an accessgranted message to the local host 220 (step 844). Upon receipt of theaccess granted message, the local host 220 activates an access controldevice 312 permitting the holder of the credential 216 to access theasset (step 848). The activation of the access control device 312 mayinclude unlocking a lock, releasing a latch, or permitting access to afinancial or electronic file.

FIG. 9 depicts a communications diagram between a credential 216 and alocal host 220 in accordance with at least some embodiments of thepresent invention. Initially, the credential 216 and local host 220mutually authenticate with one another (step 904). After mutualauthentication has occurred, the local host 220 encrypts a number ofdifferent pieces of data together into a message (step 908). Theencrypted data may include a random number (Rand), the local host ID 586(LockID), and current time information. After the message and itscontents are properly encrypted, the local host 220 transmits theencrypted message (step 912).

In step 916, the encrypted message is received by the credential 216.After the credential 216 receives the encrypted message it passes themessage to the controller 408 where the message is decrypted (step 920).Any known type of encryption/decryption scheme, whether symmetric orasymmetric, may be employed to protect the message during transmission.

After the message has been decrypted, the controller 408 runs theappropriate access decision application 416 (step 924), as the memorymay contain multiple access decision applications. Part of running theaccess decision application 416 generally includes making an accessdecision and generating a message consistent with the decision (step928). For example, if an access granted decision is made by thecredential 216, then a grant access message is generated. Alternatively,if an access denied decision is made by the credential 216, then a denyaccess message is generated. The controller 408 then encrypts thecontents of the message according to either the same encryption protocolthat was employed by the local host 220 or a different encryptionprotocol (step 932). Thereafter, the controller 408 sends the encryptedmessage to the communication interface 404 for transmission (step 936).

The message transmitted by the credential 216 is subsequently receivedby the local host 220 (step 940). After the message is received, thecontroller 308 decrypts the message (step 944). Thereafter, the contentsof the decrypted message are stored in memory 216 of the local host 220(step 948). Of course, the contents of the message may have also beenstored in the log file 552 of the credential 216 prior to transmissionof the message.

The local host 220 then sends a control signal to the access controldevice 312 causing the access control device 312 to act in accordancewith the access decision made by the credential 216 (step 952). In otherwords, if the credential 216 decided that access should be granted, thenthe access control device 312 is manipulated such that access to theasset protected by the local host 220 can be obtained. However, if thecredential 216 decided that access should be denied, then the accesscontrol device 312 is manipulated or left alone such that access to theasset is denied.

In accordance with other embodiments of the present invention, thecredential 216 may have access to a positioning satellite signal. Insuch an embodiment, the credential 216 can infer what local host 220 itis talking to based on its known position. This eliminates therequirement of the local host 220 providing a local host ID to thecredential 216. The satellite may also provide the current time to thecredential 216 such that the credential 216 could make an accessdecision without receiving any information from the local host 220.Mutual authentication and an access decision message transmission fromthe credential 216 to the local host 220 would be the onlycommunications required between the credential 216 and the local host220.

In other alternative embodiments, the application data is protected witha public-key cryptography using an asymmetric key Ka unique to aparticular application. The key Ka would be shared with the privilegeserver 204. Alternatively, the key is a symmetric key diversified from amaster key. In such a scheme, the privilege server 204 knows publicinformation such as a User ID 524. The secret diversified key is derivedfrom the public information using a hash or encryption algorithm with asecret master key known only to the privilege server 204. Thediversified key is pre-calculated and stored on the credential 216 andcalculated by the privilege server 204 during authentication.

In one embodiment, the authentication is performed on a static orrolling message exchanged between the credential 216 and thereader/writer 212 or local host 220. In another embodiment, thereader/writer 212 or local host 220 could have a random number generatorthat would be used to create a random message to use in theauthentication.

In another embodiment, the user ID 524 assigned for a particularapplication is replaced with the credential ID 504, which could be readand cross-referenced with the user information for the purpose ofassigning privileges.

In another embodiment, the reader/writer 212 or local host 220 couldalso be equipped with a secondary authentication device that requires apersonal identification number (PIN). Either the credential 216 wouldread the PIN and compare it with a stored value as part of the accessdecision or the credential would transmit its stored value to the readerso that the reader could compare PIN values as part of the accessdecision.

In still another embodiment, biometric identification information can bestored on the credential and compared to a live scan biometricidentification obtained either by the credential or transmitted from anexternal scanner. The credential 216 performs a match between the storedand live scan biometric data and uses the positive or negativecomparison as part of the access decision. Alternatively, authenticationis performed using a session key transported to the local host 220 bythe credential 216 using a Kerberos scheme.

In accordance with one embodiment of the present invention, the controlschedule 532 uses an area control scheme requiring the credential 216 totrack its recent usage history. In an area control scheme a pair of areanumbers is associated with the local host 220. For example, each localhost 220 is a portal permitting egress from one area, and ingress toanother area. This area control information is written to the credential216 by the validation server 208 and may be in the form of last areaentered and/or a timestamp from the access granting event to the lastarea entered.

In yet another embodiment where the local host 220 does not have accessto a clock, the application data may contain a counter that permits aspecified number of accesses with a given local host ID 586. The numberis counted down each time that access is given for local host ID 586 andthe permission is denied after the counter reaches a lower limit, suchas zero. Alternatively, the credential 216 may be set to expire by meansof a decay constant. The decay constant could be electric charge leavinga capacitor or battery, magnetic field, or other means that can bedetected and reset.

In still another embodiment, the application data is stored on thecredential 216 in a structured order, for example a door list in column1, a two-man-rule name list in column 2, and other information in column3 and so on. Then a filter that is coded to read data from a givencolumn/row on the credential 216 may be stored on the local host 220.This template contains no other information other than which row andcolumn to read from a credential 216. This template can be stored on thelocal host 220 memory 316. In use for decision-on-card, the templatewill be read by the credential 216 and the identified information willbe used in making the access decision.

As can be appreciated by one skilled in the art, additional applicationsmay be employed using a credential 216 that is capable of making its ownaccess decisions. In one embodiment, the credential 216 may be used forloyalty programs that, for example, offer a free or discounted productor service after a prescribed number of products or services have beenpurchased.

Two-Man-Rule on Reader

The two-man-rule controls access to sensitive areas where a minimum oftwo people are required at all times. Most of the logic is contained inthe reader/writer 212 or local host 220. The access control device 312is normally locked and two valid credentials 216 are presented forentry. Either two readers can be used to ensure near simultaneity or asingle reader can be used to read two credentials 216 in temporallyclose succession. The reader notes that two valid credentials 216 havebeen read and then once the access control device 312, such as a door,has been opened and closed, a reader on the opposite side of the doormust again read the same two credentials 216 to ensure that both usersentered. Once two users are in the secure area, additional valid usersare allowed access. Exiting the secure area follows the same procedurein reverse where the last two people must exit together or where nosingle individual is permitted to remain in the searched area. Anyviolation of the procedure will set off an alarm. Log files may be kepton both the reader and the credentials 216. The information stored onthe credential 216 can include the identification of other credentials216 used to enter the room during the same time period. This methodrequires that the reader has a way of detecting that the door or similaraccess control device 312 has been closed and locked.

Two-Man-Rule on Credential

An alternative approach is to put the two-man-rule on the credential216. In one embodiment, two valid credentials 216 are presented to anoutside reader. The credential 216 recognizes that the reader usestwo-man-rule and the reader has to cooperate with the credentials 216 byproviding information to the second credential 216 that a valid firstcredential 216 has just been read. The reader can be programmed to usethe two-man-rule by transmitting the timestamp of the most recently readvalid credential 216 and by having the ability to interpret twodifferent control commands from the credential 216. One possible controlcommand is that the credential 216 is valid but without the command tounlock the door. This occurs when a credential 216 verifies that it isvalid, but that the timestamp received from the reader of the mostrecent valid credential 216 is too old (for example more than fiveseconds). The second control command, for example, is to unlock theaccess control device 312. This occurs when the credential 312 verifiesthat it is valid and that the timestamp from the most recently readvalid credential 312 is within the allowed time period defined in thetwo-man-rule. An example two-man-rule is shown as follows:

1) The first valid credential 216 sends a message to the reader that itis valid and the reader does not immediately unlock the door but insteadwaits for a second valid credential 216.

2) The second credential 216 receives information from the reader afirst credential 216 has just been validated.

3) The second credential 216 has information that this door usestwo-man-rule and should, after receiving information about the firstvalid credential 216, check its own validity with a positive checkresulting in the credential 216 sending a control command for the accesscontrol device 312 to be unlocked or released.

Man-Trap

A man-trap provides security against piggybacking. The configurationrequires two doors on either side of a vestibule area and each doorhaving a reader on both the inside and outside of the area. Both doorsare normally locked and are generally unlocked in a specified order.Normal operation requires that readers on both doors are able to detectif either of the other doors are closed and locked or open. In normaloperation, a credential 216 is presented to a first reader outside theenclosed area on or near the first door. A valid credential 216 willunlock this first door allowing the person to enter the vestibule. Thefirst door closes and locks before the second door can be unlocked.After the first door is closed and locked the credential 216 can bepresented to the second door and, if valid, the second door will unlock.

Pseudo Man Trap

A pseudo-man-trap can be implemented on non-networked readers. Withnon-networked readers, the second door is unaware of whether or not thefirst door is closed and locked or is open; therefore, it cannot berequired to remain locked while the first door is open or unlocked (thismay be overcome by a local wired or wireless network). Similar resultscan be obtained by using the credential 216 to carry a message from thefirst door to the second door regarding its lock-status. The operationof a pseudo-man-trap is described as follows:

1) The credential 216 is presented to the outside reader of the firstdoor and if valid the door is unlocked.

2) After entering the enclosure and waiting for the door to close andlock, the credential 216 is presented to the inside reader of the firstdoor. The card receives a secure message, possibly using a key shared bythe two doors, stating that the first door is closed and locked.

3) The credential 216 is presented to the second door and both thecredential 216 validation and the first-door-status are checked. If bothconditions are satisfied the second door is unlocked.

The present invention, in various embodiments, includes components,methods, processes, systems and/or apparatus substantially as depictedand described herein, including various embodiments, subcombinations,and subsets thereof. Those of skill in the art will understand how tomake and use the present invention after understanding the presentdisclosure. The present invention, in various embodiments, includesproviding devices and processes in the absence of items not depictedand/or described herein or in various embodiments hereof, including inthe absence of such items as may have been used in previous devices orprocesses, e.g., for improving performance, achieving ease and\orreducing cost of implementation.

The foregoing discussion of the invention has been presented forpurposes of illustration and description. The foregoing is not intendedto limit the invention to the form or forms disclosed herein. In theforegoing Detailed Description for example, various features of theinvention are grouped together in one or more embodiments for thepurpose of streamlining the disclosure. This method of disclosure is notto be interpreted as reflecting an intention that the claimed inventionrequires more features than are expressly recited in each claim. Rather,as the following claims reflect, inventive aspects lie in less than allfeatures of a single foregoing disclosed embodiment. Thus, the followingclaims are hereby incorporated into this Detailed Description, with eachclaim standing on its own as a separate preferred embodiment of theinvention.

Moreover though the description of the invention has includeddescription of one or more embodiments and certain variations andmodifications, other variations and modifications are within the scopeof the invention, e.g., as may be within the skill and knowledge ofthose in the art, after understanding the present disclosure. It isintended to obtain rights which include alternative embodiments to theextent permitted, including alternate, interchangeable and/or equivalentstructures, functions, ranges or steps to those claimed, whether or notsuch alternate, interchangeable and/or equivalent structures, functions,ranges or steps are disclosed herein, and without intending to publiclydedicate any patentable subject matter.

1. A method, comprising: storing information at a stand-alone reader,the information stored on the stand-alone reader including a list ofdevices and/or users that are allowed to access an asset protected bythe stand-alone reader; storing information at a mobile device, theinformation stored on the mobile device including a list of readers thata holder of the mobile device is allowed to access; exchangingcommunications between the stand-alone reader and the mobile device suchthat at least one of the following occurs: (i) the stand-alone readercommunicates at least some information stored on the stand-alone readerto the mobile device; and (ii) the mobile device communicates at leastsome information stored on the mobile device to the stand-alone reader;and based on the exchange of communications between the stand-alonereader and the mobile device, making an access control decision for themobile device.
 2. The method of claim 1, wherein the access controldecision is made by the mobile device.
 3. The method of claim 2, whereinthe mobile device communicates results of the access control decision tothe stand-alone reader thereby allowing the stand-alone reader toimplement an action consistent with the access control decision.
 4. Themethod of claim 3, wherein the action includes unlocking a door.
 5. Themethod of claim 1, wherein the access control decision is made by thestand-alone reader.
 6. The method of claim 1, wherein the access controldecision is made by both the stand-alone reader and the mobile device.7. A system, comprising: a reader configured to store a list of devicesand/or users that are allowed to access an asset protected by thereader; a credential configured to store a list of readers that a holderof the credential is allowed to access; wherein the reader andcredential are configured to exchange communications with one anothersuch that at least one of the following occurs: (i) the readercommunicates at least some of the information stored in the list ofdevices and/or users to the credential; and (ii) the credentialcommunicates at least some of the information stored in the list ofreaders to the reader; and wherein, based on the exchange ofcommunications between the reader and credential, an access controldecision is made for the credential.
 8. The system of claim 7, whereinthe access control decision is made by the credential.
 9. The system ofclaim 8, wherein the credential comprises a cellular phone.
 10. Thesystem of claim 8, wherein the credential communicates results of theaccess control decision to the reader, thereby allowing the reader toimplement an action consistent with the access control decision.
 11. Thesystem of claim 10, wherein the action includes unlocking a door. 12.The system of claim 7, wherein the access control decision is made bythe reader.
 13. The system of claim 12, wherein the reader comprises astand-alone reader.
 14. The system of claim 7, wherein the accesscontrol decision is made by both the reader and the credential.
 15. Thesystem of claim 7, wherein the reader and credential exchangecommunications via a proximity-based communication protocol.
 16. Thesystem of claim 15, wherein the proximity-based communication protocolutilizes a Radio Frequency (RF) inductive field.
 17. The system of claim7, wherein the asset comprises a physical asset.
 18. The system of claim7, wherein the asset comprises a logical asset.
 19. The system of claim7, wherein results of the access control decision are communicated bythe credential back to a control panel.
 20. The system of claim 19,wherein the results of the access control decision are communicated viaa mobile communications network.